Which tissue forms the base of the gingival sulcus?

Which tissue forms the base of the gingival sulcus?

• A. Junctional epithelium
• B. Gingival connective tissue
• C. Oral mucosa
• D. Alveolar bone

Answer: (A)

The base of the gingival sulcus is formed by the junctional epithelium. This thin, non-keratinized epithelium lines the sulcus and attaches directly to the tooth surface (primarily to cementum near the CEJ) through a basement membrane and hemidesmosomes, creating the sealed boundary between the tooth and gingiva. This attachment defines the bottom of the sulcus and acts as the first barrier to bacterial invasion. Gingival connective tissue lies beneath the junctional epithelium, forming the supporting lamina propria but not lining the sulcus base. Oral mucosa refers to the broader mucosal tissue of the mouth and includes several tissue types, not specifically the sulcus boundary. Alveolar bone forms the tooth socket and supporting bone structure, not the sulcus lining.

The base of the gingival sulcus is formed by the junctional epithelium. This thin, non-keratinized epithelium lines the sulcus and attaches directly to the tooth surface (primarily to cementum near the CEJ) through a basement membrane and hemidesmosomes, creating the sealed boundary between the tooth and gingiva. This attachment defines the bottom of the sulcus and acts as the first barrier to bacterial invasion.

Gingival connective tissue lies beneath the junctional epithelium, forming the supporting lamina propria but not lining the sulcus base. Oral mucosa refers to the broader mucosal tissue of the mouth and includes several tissue types, not specifically the sulcus boundary. Alveolar bone forms the tooth socket and supporting bone structure, not the sulcus lining.